Air purifier



FIG. 1 is a perspective view of an air purifier embodying my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a right side view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view of the design with the base removed.

The broken line showing of parts of the air purifier is included for the purpose of illustrating use and environment and forms no part of the claimed design. 

The ornamental design for an air purifier, as shown and described. 